A novel general-purpose four-phase-shift modulation method for improving the dynamic performance of dual active bridges

Abstract

The present invention provides a novel general-purpose four-phase-shift modulation method for improving the dynamic performance of dual active bridges. All carrier signals remain synchronized. The general-purpose four-phase-shift modulation method adjusts the corresponding parameters by changing the parameters of the comparison registers in each carrier. phase shift angle. The control method proposed by the present invention is based on the traditional phase-shift control method, and only needs to measure the input and output voltages without adding auxiliary circuits. Compared with other control methods, the method proposed by the present invention completes the dynamic response instantaneously, does not need a transition process, and does not need to detect the inductance current, and the whole control process has nothing to do with the inductance value. The method proposed in the present invention reduces the cost and computational complexity, realizes fast dynamic response of the circuit and eliminates the DC bias of the inductor current during the response process, and at the same time, the method proposed in the present invention can be applied to hard switching, soft switching, unidirectional power transmission, All application scenarios such as two-way power transmission are also applicable to all control methods such as single phase-shift modulation and triple phase-shift modulation.

Description

technical field [0001] The invention relates to a novel universal four-phase-shift modulation strategy for improving the dynamic performance of a dual active bridge, relates to a dual active bridge DC converter, and belongs to the technical field of power electronics. Background technique [0002] With the continuous development of power electronics technology and the diversification of application scenarios, more and more application scenarios require bidirectional transmission of electric energy. Bidirectional isolated DC / DC converters have been used more and more widely. Dual active bridge circuits are widely used because of their simple control, easy implementation of soft switching, and high efficiency. figure 1 It is a traditional dual active bridge circuit topology. The original and secondary sides are respectively composed of four MOSFETs. Each full bridge can be divided into two bridge arms, and there are four bridge arms L 1 -L 4 , each bridge arm consists of up...

AI Technical Summary

Problems solved by technology

However, with the sudden change of the phase shift angle, the traditional method will cause the transient bias current of the inductor due to the sudden change of the duty cycle

This results in slow dynamic response, increased current stress, increased losses

At the same time, the bias current may also cause the saturation of the inductor, which will lead to serious consequences such as loss of converter function or circuit damage.

[0004] The Chinese invention patent with the application number CN201410678003.0 and the name "A Transient Phase-Shift Control Method for Dual-Active Full-Bridge DC Converter" proposes a method for eliminating bias current for single phase-shift control. However, the transient DC bias suppression capability cannot be achieved in the multi-phase shift modulation strategy

[0005] The Chinese invention patent with the application number CN202010365209.3 and the name "Universal Phase Shift Control Method for Transient DC Bias of Dual Active Bridge DC Converters" proposes a method for eliminating bias current for multi-phase shift control , but the control process is more complicated, and the transient transition process affects the response speed

[0006] To sum up, in the process of dynamic change of dual active bridge load based on the traditional single-phase-shift modulation strategy, it is very easy to generate a DC bias of the inductor current, which will seriously affect the dynamic response and reliability of the converter.

Existing solutions have certain limitations

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